Inhalator



lJuly'24, 1962 y H HIRTZ ET AL 3,045,670

INHALAfroR 2 Sheets-Sheet 2 ufr/111111111111111111111//1/1/1/l I I I 0/NVENTOR HANS HIKTL Ma C-HAEL. S. Sfluf Hmmm United States The inventionrelates to an inhalator and more particularly to an inhalator fortreatment of the respiratory ducts of a patient with heated andmedicated air.

In a portable inhalator of the type described, it is desirable to makethe heating device, which commonly consists of an electric resistanceheater as small and as efcient as possible. It is furthermore desirablethat such a device `be rugged and capable of withstanding roughhandling. It is furthermore necessary that it be safe and that the userbe protected lfrom accidental contact with the heating element or withany portion of the inhalator heated to a high temperature.

It is therefore a primary object of the invention to provide aninhalator the accessible portions of which remain cool during operationof the inhalator.

Another object is the provision of such an inhalator which utilizes tothe fullest possible extent the thermal energy supplied by the heater.

It is a further object fof the invention to use the inhaled air or otherga-s as an insulating means for keeping the outside of the inhalator ata safe, low temperature.

An additional object of the invention is the provision of such aninhalator which is readily disassembled for cleaning, sterilization, orrepair.

Yet another object is the provision of an inhalator in which exhaled gasis substantially completely vented to the atmosphere and replaced byyfresh gas substantially without mixing.

The novel features which are considered as characteristic for theinvention are set forth in particular in the appended claims. Theinvention itself, however, both as to its construction and its method ofoperation, together with additional objects and advantages thereof, willbe best understood from the following description of speciiicembodiments when read in connection with the accompanying drawings, inwhich:

FIG. 1 shows a side elevation, pantly in axial section, of a preferredembodiment of the inhalator of the invention;

FIG. 2 is a sectional view of a detail of the apparatus of FIG. 1 takenalong line II-II of FIG. l;

FIG. 3 illustrates a portion of the device of FIG. 2;

FIG. 4 is a side elevation, largely in axial section, of a modifiedembodiment of ythe invention, with a portion broken away; and

FIG. 5 is a section through the device tof FIG. 4 in a plane along line5--5,

Referring now to the drawings and particularly to FIG. l, there is showna -face mask of resilient material shaped to t a human face in asubstantially gas-tight manner. The face mask 10 is releasably fastenedto a connecting member 11 which connects the face mask to a handleportion 14 of an inhalator containing a heating element 12 arranged in aheating chamber 19. The heating chamber is enclosed by a cylindrical`container 17 communicating at one end by an axial opening with theconnecting member 11. Heating chamber 19 com-municates Iby radialopenings 18 in the cylindrical wall of container 17 adjacent the endthereof remote from the aforementioned axial opening with an annularinsulating space 13 which extends substantially over the entire lengthof container 17 and is bounded radially outward therefrom atet by a wall15 of cylindrical shape which constitutes the outer wall of the handleportion of the inhalator.

insulating space 13 communicates with the atmosphere by means of radialopenings 16 in outer wall 15 which are longitudinally spaced fromopenings 18 in container 17 and serve as air inlets, the air flowingdownward through insulating space 13, as shown in FIG. l, passingthrough openings 18 in to the heating chamber 19 and flowing upwardtherein past the heating element 12 countercurrent to the iiow of gas inspace 13 to leave the heating chamber through the axial opening in thetop thereof, thereby heating container 17 from the inside. The airflowing downward in insulating space 13 prevents any heat from beingtransmitted from the outer surface of container 17 to the outer wall 15of handle portion 14.

A bottom member 46 of heat-insulating material seals insulating space 13and heating chamber 19 from the atmosphere. Openings 18 in the wall ofcontainer I17 are spaced a small distance lfrom bottom member 46 so thata radially inward flow of relatively cool air is maintained above thesurface of insulating 'bottom member 46 and the outer surface of bottommember 46 remains cool during operation of the inhalator. Since thetemperature diiferential between the inner and outer surfaces of bottommember 46 is small, heat losses through the bottom are negligible. Anyheat transmitted from the heating chamber 19 through the cylindricalwall of container 17 is practically in its entirety utilized to preheatthe air entering the inhalator through inlet opening 16 and flowingthrough insulating space 13.

A thermostatic switch 23 is arranged in heating chamber 19 to controlthe iiow of current from line cord 22 to heater element 12 so as tomaintain the temperature of the air leaving the heating chambersubstantially constant. Switch 23 which may for example contain abimetallic temperature-sensitive element of adjustable tension may beset for a variety of actuating temperatures by a setting knob 22connected to the switch for adjustment of the tension of the bimetallictemperature-sensitive element of the switch.

Heated air leaving the heating chamber 19 passes through a check valve24 spring-biased towards the closed position and Iopened by a pressuredrop existing in a direction lfrom heating chamber 19 towards the cavity20 of connecting member 11. Check Valve 24 is thus normally closed andis opened when air is inhaled through :face mask 10. A portion of checkvalve 24 is clamped between opposite faces of connecting member 111 andhandle portion 14 in the assembled condition of the inhalator. Whenconnecting member 11 is separated from lthe handle portion 14 byunscrewing, the check valve 24 is released :for cleaning, sterilization,or other maintenance operations.

A second check valve 25 is arranged over an opening 27 in connectingmember 1'1 which communicates with the atmosphere. Check valve 25 isreleasably fastened to connecting member 1-1 by means of -a threaded cap26 and is spring-biased towards the closed position in such a mannerthat it will vent connecting member 11 to the atmosphere when thepressure in cavity 2G exceeds atmospheric pressure by a predeterminedamount, as during exhalation into the face mask 10 thus substantiallypreventing mixing of exhaled and inhaled air.

The air drawn in by inhalation through the handle portion 14 passes fromcavity 20 to face mask 10 through openings 21 in the connecting member.The inhaled air may be medicated by means of -a medication carrier 28best seen in FIG. 2 and comprising a perforated tube 34 iilled withIabsorbent material (not shown) such -as cotton wool saturated withvolatile medication. Tube 34 is inserted into cavity 20 through anopening 31 in connecting member 11, the opening extending into anoutwardly 3 threaded nipple 32 which is closed by a threaded cap 30 towhich one end of perforated tube 34 is axially fastened. The other endof tube 34 is tapered to form an open portion 29 of very small internaldiameter.

Cap 30 may be unscrewed from nipple 32 and engaged with the threadedneck of a medicine bottle 33 in such a manner that carrier 2S extendsinto the bottle as indicated by dot-and-dash lines in FIG. 3. Medicationmay thus be absorbed in the material contained in tube 34 through theperforations and through the small opening in the tapered portion 29.

The embodiment of the invention illustrated in FIG. 4 is structurallysomewhat modied from that of FIGS. l, 2 and 3, but functions in ananalogous manner.

Air enters the handle portion of the device through inlet openings 34and passes countercurrent first through two concentric annularinsulating spaces 35, 36, then to enter a heating chamber 39 throughopenings 37 in the wall thereof. The double rings of insulating spacesswept by the incoming air holds the outer surface of the handlevirtually at room temperature. After passing over a heating element 38,the air enters a resilient duct 4t) shown to consist of a reinforcedhose of corrugated elastomeric material. It passes into a connectingmember 42 through a check valve permitting passage of gas only in thedirection from the duct into the connecting member. A medication carrier44 causes mixing of volatile medication with the flowing gas which isthen inhaled from face mask 41 which is equipped with a check Valve 45of a structure analogous to that of valve 25 of FIG. l to permit escapeof exhaled gas.

Whereas threaded releasable connections were generally employed lbetweenthe several elements of the inhalator of FIG. l to permit theirdisassembly for cleaning purposes and the like, only face mask beingresiliently held by friction fit in connecting member 11, resilient andfrictional engagement is utilized in the assembly of the severalportions of the device of FIG. 4. Duct 40' thus is held in a tubularextension of the handle portion of the inhalator, and itself resilientlyenvelops one end of connecting member 42, thereby holding in place thecheck valve 43 and the medication carrier 44 which is inserted inconnecting member 42 -through an opening in the wall thereof which issealed by the overlying end portion of duct 40. Face mask 41 is held byfriction in connecting member 42 and check valve 45 may be held in placeon the face mask by a resilient cap.

Instead of a single adjustable thermostatic switch, the embodiment ofthe invention illustrated in FIG. 4 is equipped with three switches 23,peripherally spaced about heating element 38 and each set for a lixedtemperature to actuate individual sections of heating element 38. Thethree thermostatic switches 23 cooperate with a threeway switch in awell known manner to permit stepwise adjustment of the temperature ofthe inhaled air.

While the 'device of the invention has been illustrated in specificembodiments, employing a face mask and utilizing atmospheric air as theinhaled gas, it will be understood that the inlet openings of the devicemay be connected to any other source of a gas that is desired to beheated prior to introduction into the respiratory ducts of a patient.Passage of the gas through the apparatus of the invention need not beactuated by the negative pressure created at the outlet of the apparatusby inhalation, but may equally be actuated by positive pressure appliedat the inlet side of the device. The scope of this invention also is notlimited to an inhalator employing a face mask, but any other outletmeans communicating with the heating chamber of the inventive `devicemay be utilized for conveying a gas heated in said chamber to therespiratory ducts which are intended to be treated.

While the invention has been illustrated and described as embodied in aportable inhalator, it is not intended to be limited to the detailsshown, since various modications and structural changes may be madewithout departing in any way from the spirit of the present invention.

Without further analysis, the foregoing will so fully reveal the gist of4the present invention that others can by applying current knowledgereadily adapt it for various applications without omitting featuresthat, from the standpoint of prior art, fairly constitute essentialcharacteristics of the generic or specific aspects of this inventionand, therefore, such adaptations should and are intended to becomprehended within the meaning and range of equivalent of the followingclaims.

What is claimed as new and desired to be secured by Letters Patent is:

1. An inhalator for treatment of the respiratory ducts of a patient,comprising in combination: a heating charnber, heating means in saidchamber for heating a gas passing through said chamber, said heatermeans being in the form of a tubular body; thermostat means in saidheating chamber and operatively connected to said heating means forautomatically regulating the latter to maintain a preselectedtemperature in said heating chamber; a hollow member substantiallyenveloping said chamber and having a wall spaced from the outside ofsaid chamber and defining therewith an insulating space; inlet means onsaid hollow member for connecting said space to a source of gas; conduitmeans spaced from said inlet means for connecting said insulating spaceto said chamber; a hollow connecting member connectable to an outletmeans and communicating with said chamber at a portion thereof coaxialwith said tubular heating means; rst check valve means interposedbetween said connecting member and said chamber to permit flow of gassubstantially only in the direction from said chamber to said connectingmember; a medication carrier adapted to hold volatile medication andreleasably arranged in said connecting member downstream of said firstcheck valve means; and second check valve means communicating with saidconnecting member for venting the latter to the atmosphere when the gaspressure on the inner face of said second check valve means exceeds apredetermined value, so that upon inhalation through said outlet meanssaid gas is drawn in sequence through said insulating space and saidheating chamber, whereby the temperature of said wall is held below thetemperature of the outside of said chamber as said gas is being heated,and gas exhaled into said connecting member through said outlet means isvented to the atmosphere.

2. An inhalator for treatment of the respiratory ducts of a patient,comprising in combination: a heating charnber, heater means in saidchamber for heating a gas passing through said chamber, said heatermeans being in the form of a tubular body; thermostat means in saidheating chamber and operatively connected to said heating means forautomatically regulating the latter to maintain a preselectedtemperature in said heating chamber; a hollow member substantiallyenveloping said chamber and having a wall spaced from the outside ofsaid chamber and dening therewith an insulating space; inlet means onsaid hollow member for connecting said space to a source of gas; conduitmeans spaced from said inlet means for connecting said insulating spaceto said chamber; a hollow connecting member connectable to an outletmeans and communicating with said chamber at a portion thereof coaxialwith said tubular heating means; irst check valve means interposedbetween said connecting member and said chamber to permit ow of gassubstantially only in the direction from said chamber to said connectingmember; a medication carrier adapted to hold volatile medication andreleasably arranged in said connecting member downstream of said iirstcheck valve means, said connecting member having an engageable portionmating an engaging portion of said carrier in sealing relationship; andsecond check valve means communicating with said connecting member forventing the latter to the atmosphere when the gas pressure in saidconnecting member exceeds a predetermined value, so that upon inhalationthrough said outlet means said gas is drawn in sequence through saidinsulating space and said heating chamber, whereby the temperature ofsaid wall is held below the temperature of the outside of said chamberas said gas is being heated, and over said medication carrier forvolatilizing a portion of said medication.

3. An inhalator for treatment of the respiratory ducts of a patient,comprising in combination: an elongated, tubular holding handle; heatingchamber means in said holding handle; heater means in said chamber meansfor heating a gas passing through said chamber, said heater means beingin the form of a tubular body; thermostat means in said heating chamberand operatively connected to said heating means for automaticallyregulating the latter to maintain a preselected temperature in saidheating chamber; a hollow member substantially enveloping said chambermeans and having a wall spaced from the outside of said chamber meansand spaced from the inner surface of said tubular handle, said walldefining with said tubular handle a first annular space closed atopposite ends thereof and with said heating chamber means a secondannular space closed at opposite ends thereof; inlet means on saidtubular handle for connecting said first annular space to a source ofgas; conduit means spaced from said inlet means for connecting saidsecond annular space to said chamber means; passage means through saidwall and spaced in longitudinal direction from said inlet and saidconduit means to provide communication between said annular spaces; ahollow connecting member releasably fastened to said handle andcommunicating with said chamber means at a portion thereof coaxial withsaid tubular heating means; and outlet means on said connecting member,so that upon inhalation through said outlet means all of the gasentering through said inlet means is drawn in sequence through saidannular spaces and said heating chamber means to be gradually heatedwhile the surface temperature of said handle is held below thetemperature of the outside of said chamber means.

4. An inhalator for treatment of the respiratory ducts of a patient,comprising in combination: an elongated, tubular holding handle; heatingchamber means in said holding handle; heater means in said chamber meansfor heating a gas passing through said chamber means, said heater meansbeing in the form of a tubular body; a hollow member substantiallyenveloping said chamber means and having a wall spaced from the outsideof said chamber means and spaced from the inner surface of said tubularhandle, said wall defining with said tubular handle a first annularspace closed at opposite ends thereof and with said heating chambermeans a second annular space closed at opposite ends thereof; inletmeans on said tubular handle for connecting said first annular space toa source of gas; conduit means spaced from said inlet means forconnecting said second annular space to said chamber means; passagemeans through said Wall and spaced in longitudinal direction from saidinlet and said conduit means to provide communication between saidannular spaces; a hollow connecting member releasably fastened to saidhandle and communicating with said chamber at a portion thereof coaxialwith said tubular heating means; and a face mask communicating with saidconnecting member, so that upon inhalation through said face mask all ofthe gas entering through said inlet means is drawn in sequence throughsaid annular spaces and said heating chamber means to be graduallyheated while the surface temperature of said handle is held below thetemperature of the outside of said chamber means.

5. An inhalator as defined in claim 4, and including duct meansinterposed respectively between said handle and said connecting member,and between the latter and said face mask, at least one of said ductmeans being flexible.

6. An inhalator for treatment of the respiratory duct of a patient,comprising, in combination, an elongated heating chamber; heater meansin the form of a tubular body in said chamber for heating a gas passingthrough said chamber; a first elongated hollow member substantiallyenveloping said chamber and having a first Wall spaced from the outsideof the chamber and defining therewith a first insulating space; a secondelongated hollow member substantially enveloping said first hollowmember and having an outer wall spaced from said first wall and definingtherewith a second insulating space; inlet means communicating with saidsecond insulating space for connecting said space to a source of gas;first passage means spaced in longitudinal -direction from said inletmeans for providing communication between said second and said firstinsulating space; second passage means spaced in longitudinal directionfrom said first passage means for providing communication between saidfirst insulating space and said heating chamber; and outlet meanscommunicating with said chamber and spaced in longitudinal directionfrom said second passage means so that upon inhalation through saidoutlet means all of the gas entering through said inlet means is drawnin sequence and countercurrently through said second insulating space,said first insulating space and said heating chamber to be graduallyheated while the temperature of said outer wall is held below thetemperature of the outside of said chamber.

References Cited in the file of this patent UNITED STATES PATENTS1,771,366 Wyss July 22, 1930 1,998,327 McGuire Apr. 16, 1935 2,084,299Borden June l5, 1937 2,241,356 Magee May 6, 1941

